Actuation assembly for an oral irrigator

ABSTRACT

An actuation assembly for an oral irrigator includes a bezel secured to or formed as part of a housing of the oral irrigator, an actuator operably connected to the bezel and moveable relative thereto, and an augmentation fluid positioned between the bezel and the actuator. The augmentation fluid modifies a frictional relationship between the bezel and the actuator to provide a predefined resistance force between the actuator and the bezel as the actuator is rotated relative to the bezel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority pursuant to 35 U.S.C. §119(e) of U.S. provisional application No. 62/302,565 filed 2 Mar. 2016entitled “Actuation assembly for an oral irrigator,” which is herebyincorporated herein by reference in its entirety

TECHNICAL FIELD

The present disclosure relates generally to health and personal hygieneequipment and more particularly, to oral irrigators.

BACKGROUND

Oral irrigators are typically used to clean a user's teeth and gums bydischarging a pressurized fluid stream into the oral cavity of a user.The fluid impacts the teeth and gums to remove debris. Many oralirrigator units include a reservoir that connects to a base unit housingthe pump and other internal components. The fluid stored in thereservoir is pulled into the pump and pressurized to deliver the fluidto the tip of a handle. These units typically include a button, knob, orother mechanism actuated by a user to vary one or more characteristicsof the oral irrigator, e.g., turn the power on or off, adjust thepressure of water expelled from the tip, etc. Conventional buttons andknobs for oral irrigators, however, are made of plastic, can bedifficult to actuate when wet, and do not provide tactile feedback to auser when actuated.

The information included in this Background section of thespecification, including any references cited herein and any descriptionor discussion thereof, is included for technical reference purposes onlyand is not to be regarded subject matter by which the scope of theinvention as defined in the claims is to be bound.

SUMMARY

In one implementation, an actuation assembly for an oral irrigatorincludes a bezel secured to or formed as part of a housing of the oralirrigator, an actuator operably connected to the bezel and moveablerelative thereto, and an augmentation fluid positioned between the bezeland the actuator. The augmentation fluid modifies a frictionalrelationship between the bezel and the actuator to provide a predefinedresistance force between the actuator and the bezel as the actuator isrotated relative to the bezel.

In another implementation, an oral irrigator includes a fluid reservoirand a housing configured to support the fluid reservoir. A pump may bepositioned within the housing and have an inlet fluidly connected to thefluid reservoir and an outlet. A motor may also be positioned within thehousing to drive the pump. A power source may further be positionedwithin the housing to provide electricity to the motor. An irrigatorhandle with a fluid outlet may be fluidly connected via a hose to theoutlet of the pump. A first bezel may be secured to or formed as part ofthe housing and positioned about a first opening in the housing. Acentral aperture may be defined within the first bezel. A first actuatormay be operably connected to the first bezel and moveable relativethereto. The first actuator may include a first boss that extendsthrough the central aperture in the first bezel and the first opening inthe housing and may be operably connected to a switch that actuates thepower source. A first augmentation fluid may be positioned between thefirst bezel and the first actuator. The first augmentation fluidmodifies a frictional relationship between the first bezel and the firstactuator to provide a predefined resistance force between the firstactuator and the first bezel as the first actuator is rotated relativeto the first bezel.

The oral irrigator may further include a second bezel secured to orformed as part of the housing and positioned about a second opening inthe housing. A central aperture may be defined within the second bezel.A second actuator may be operably connected to the second bezel andmoveable relative thereto. The second actuator may include a second bossthat extends through the central aperture in the second bezel and thesecond opening in the housing. The second boss may be operably connectedto a valve that controls fluid pressure in the fluid traveling from thepump to the handle. A second augmentation fluid may be positionedbetween the second bezel and the second actuator. The secondaugmentation fluid modifies a frictional relationship between the secondbezel and the second actuator to provide a predefined resistance forcebetween the second actuator and the second bezel as the second actuatoris rotated relative to the second bezel.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. A moreextensive presentation of features, details, utilities, and advantagesof the present invention as defined in the claims is provided in thefollowing written description of various embodiments of the inventionand illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front isometric view of an oral irrigator.

FIG. 2 is a front elevation view of the oral irrigator of FIG. 1.

FIG. 3A is a simplified right side elevation view of fluid managementcomponents of the oral irrigator of FIG. 1 with select components hiddenfor clarity.

FIG. 3B is a rear isometric view of the oral irrigator of FIG. 3A.

FIG. 3C is a partial view of the power assembly components of an oralirrigator of FIG. 3A.

FIG. 4 is a simplified left side elevation view of fluid managementcomponents of the oral irrigator of FIG. 3A.

FIG. 5 is a cross sectional view of the oral irrigator of FIG. 3 takenalong line 5-5 in FIG. 1.

FIG. 6A is a front isometric view of a first example of an actuationassembly of FIG. 1.

FIG. 6B is a cross sectional view of the first actuation assembly takenalong line 6B-6B in FIG. 6A.

FIG. 7A is a front isometric view of a second example of an actuationassembly of FIG. 1.

FIG. 7B is a cross section view of the second actuation assembly alongline 7B-7B in FIG. 7A.

FIG. 8A is an exploded view of the first actuation assembly of FIG. 6A.

FIG. 8B is a cross sectional view of the first actuation assembly alongline 8B-8B in FIG. 8A.

FIG. 9A is an exploded view of the second actuation assembly of FIG. 7A.

FIG. 9B is a cross sectional view of the second actuation assembly alongline 9B-9B in FIG. 8A.

FIG. 10A is a front isometric view of a bezel of the actuation assemblyof FIG. 6A.

FIG. 10B is a rear isometric view of the bezel of FIG. 10A.

FIG. 10C is a rear elevation view of the bezel of FIG. 10A.

FIG. 11A is a front isometric view of a bezel of the actuation assemblyof FIG. 7A.

FIG. 11B is a rear isometric view of the bezel of FIG. 11A.

FIG. 11C is a rear elevation view of the bezel of FIG. 11A.

FIG. 12A is a front isometric view of an actuator of the actuationassembly of FIG. 6A.

FIG. 12B is a rear elevation view of the actuator of FIG. 12A

FIG. 12C is a rear isometric view of the actuator of FIG. 12A.

FIG. 12D is a bottom plan view of the actuator of FIG. 12A.

FIG. 13A is a front isometric view of an actuator of the actuationassembly of FIG. 7A.

FIG. 13B is a rear elevation view of the actuator of FIG. 13A.

FIG. 13C is a rear isometric of the actuator of FIG. 13A.

FIG. 13D is a bottom plan view of the actuator of FIG. 13A.

DETAILED DESCRIPTION

An example of the present disclosure includes an oral irrigator havingone or more user actuation assemblies for selecting or adjustingcharacteristics (e.g., pressure, power, etc.) of the oral irrigator orthe fluid output thereof. Each actuation assembly may include a bezel,an actuator, a grip enhancement surface, and an augmentation fluidpositioned between the actuator and the bezel that enhances the tactilefeel of the actuation assembly, provides feedback to the user, providesshock absorption, and varies the perceived interaction forces betweenthe knob and the internal components of the oral irrigator.

For example, in some embodiments, as a user operates the actuator, aninitial force spike transmitted from the user to the actuator assemblyis absorbed by the augmenting fluid, dampening the force and creating asoft feel for the user. When the user reaches a desired adjustment andstops the movement of the actuator, the augmentation fluid absorbs aportion of the force such that the user experiences a soft stop.

The user actuation assembly also acts to reduce noise of the oralirrigator. Typical knobs and buttons for oral irrigators create noise asthey are actuated by a user and/or transmit noise from the interioroperating components of the irrigator (e.g., pump, motor, etc.) to theoutside of the irrigator housing. The augmentation fluid of the useractuation assembly reduces noise by preventing or dampening sound waves[transmission of] through the actuation assembly to the outside of theoral irrigator unit. The augmentation fluid also reduces frictionalinteraction between various components within the actuation assembly,which further reduces noise.

The augmentation fluid characteristics, the form of a gap between thebezel and actuator in which the augmentation fluid is received, or both,can be modified to vary the user experience. For example, changing theviscosity of the augmentation fluid can result in a softer feel by theuser. As another example, varying the gap between the two components cancreate a softer or stronger feel for the user. The augmentation fluidmay increase the force required by a user to turn or actuate the knob,creating an appearance of a “high end” actuator that may “feel” like itis manufactured out of more expensive materials, such as metals, ratherthan plastics.

Additionally, the bezel and actuator may each include curved interactionsurfaces that interface with one another via the augmentation fluid. Theinteraction surfaces are curved so as to reduce noise as the actuatorrotates relative to the bezel. In an embodiment, the bezel interactionsurface may be concavely curved whereas the actuator interaction surfacemay be convexly curved and the augmentation fluid may be positionedbetween the two surfaces. The curvature reduces noise as the actuator isrotated, and generates a desired feel for the actuator. In instanceswhere the interaction surfaces are planar or uncomplimentary to oneanother, the actuator will create noise as it is turned, which isundesirable. On the contrary, using a complementary bell shape (e.g.,two mating arcs where one is convex and the other is concave) reducesnoise as the actuator is turned, providing an enhanced user experience.

In some embodiments, the oral irrigator includes two user actuationassemblies. In these embodiments, a first actuation assembly may controlthe electrical power to turn the unit on or off, where rotation in afirst direction activates the oral irrigator and rotation in a seconddirection deactivates the oral irrigator. A second actuation assemblymay control the fluid pressure of the irrigator, such that rotation ofthe actuator in a first direction increases the pressure and rotation ina second direction decreases the pressure.

Additionally, in some embodiments, the user actuation assembly includesa grip enhancement member. The grip enhancement member increases thefrictional contact between the user and the actuation assembly to allowa user to more easily actuate the actuator. Oral irrigators aretypically operated in wet environments, such as bathrooms, and buttonscan be difficult to grasp when wet, making it difficult for a user toactuate a particular button or function of the oral irrigator. The gripenhancement member allows a user, even with wet hands, in instanceswhere the enhancement member is wet, to easily move the actuationassembly in a desired manner. Additionally, in some embodiments, theactuator may be plastic or a similar material and the grip enhancementmember may be a metal formed sleeve with a textured surface, whichallows the user to interact with a frictional interface, making graspingand manipulating easier. Furthermore, as the augmentation fluidincreases the friction between the actuator and the bezel, the actuatormay require additional force to operate. The grip enhancement memberincreases the traction between a user's fingers and the actuator toallow a user to more easily rotate (or otherwise manipulate) theactuator.

With reference now to the figures, the oral irrigator of the presentdisclosure will be discussed in more detail. FIGS. 1 and 2 illustratevarious views of an oral irrigator. With reference to FIGS. 1 and 2, theoral irrigator 100 includes a base 102, a reservoir 104, a handle 106,connection to the handle 106, a tip 108, a hose 110 fluidly connectingthe handle 106 to the base 102, a first actuation assembly 122, and asecond actuation assembly 322. It should be noted that the oralirrigator unit shown in FIGS. 1 and 2 may be a “complete care” unit andinclude an optional electric toothbrush 112 therewith. However, in manyembodiments, the toothbrush 112 may be omitted. Each of the maincomponents of the oral irrigator 100 will be discussed, in turn, below,but it should be noted that many other types of oral irrigators andinternal components (e.g., motors, pumps, etc.) may be used with theactuation assemblies 122, 322 and the below discussion is meant asillustrative only.

With reference to FIGS. 1 and 2, the reservoir 104 stores fluid, such aswater, for use with the oral irrigator 100. The reservoir 104 includes afluid container compartment 114 that may include a lid 116 positioned onthe top edge to help prevent debris from falling into the fluid. Thereservoir 104 is typically seated on the base 102 and is fluidlyconnected to the handle 106 through the hose 110.

In some embodiments, the oral irrigator 100 may include a storagecompartment 118 with a storage lid 120. The storage compartment 118 maybe used to house different tips 108 for the handle 106, such as ones fordifferent users, different pressures, or that include brush heads or thelike. As shown in FIGS. 1 and 2, the tip storage compartment 118 islocated adjacent to and formed partly with the reservoir 104. However,in other embodiments, the storage compartment 118 may be defined withinthe reservoir lid 116 or the like.

The handle 106 is fluidly connected to the reservoir 104 and isconfigured to be grasped by a user to direct fluid pumped from thereservoir 104 into the user's mouth. The tip 108 is connected to thehandle 106 and may be releasable therefrom.

The base 102 is defined by a housing 103 that supports the reservoir104, the storage compartment 118, the toothbrush 112, and the handle106. The housing 103 forms a shell or exterior of the oral irrigator 100and houses the various internal components that drive the oral irrigator100. The housing 103 may be made as a single element or may be formed ofmultiple components secured together. The actuation assemblies 122, 322are connected to the housing 103 and extend through apertures in thehousing 103 to the interior of the base 102 to actuate mechanisms of theoral irrigator 100 that are housed within the base 102. FIGS. 3A-5illustrate various views of the internal components of the base 102. Theinternal components may include a pump assembly 128, a pressure assembly130, a control housing 140, and a power assembly 144. The firstactuation assembly 122 engages with and controls the power assembly 144and thus the pump assembly 128, and the second actuation assembly 322engages with and controls the pressure assembly 130 to vary the pressureof the fluid pumped to the handle 106 from the assembly 128.

The pump assembly 128 pumps fluid from the reservoir 104 to the tip 108and may include a motor 126, a pump inlet 134, a pump body 136, achassis 132, a gear assembly cover 138, and one or more pump valves 135for regulating flow into and out of the pump body 136. The pump assembly128 may be substantially any type of pumping element and include desiredcomponents for actuating fluid flow from the reservoir 104 to the tip108. For example, the pump assembly 128 may include a connecting rod,piston, and gear assembly (not shown, housed beneath the gear assemblycover 138) that are interconnected together and to the motor 126 toalternatively pull a vacuum force to fill the pump body 136 with fluidfrom the reservoir 104 and exert a push force to dispel the fluid fromthe pump body 136 towards the tip 108. Examples of pump assemblies 128that can be used are disclosed in U.S. patent application Ser. No.11/361,749 entitled “Storage Container for Water Jet Reservoir”; andSer. No. 14/956,017 titled “Oral Irrigator”, both of which areincorporated by reference herein.

The pressure assembly 130 adjusts the fluid pressure after output by thepump assembly 128. In some embodiments, the pressure assembly 130 may bean electronic control and vary the voltage applied to the motor 128 ofthe pump to electronically reduce the pressure of the pump assembly 128(see, e.g., U.S. patent application Ser. No. 14/208,806 entitled “OralIrrigator with Integrated Lid and Base”, which is hereby incorporated byreference herein). In other embodiments, the pressure assembly 130mechanically changes one or more characteristics of a flow path of fluidin the pump body 136, such as by including a bypass channel, to reduceor increase the pressure (see, e.g., U.S. patent application Ser. No.11/361,749 entitled “Storage Container for Water Jet Reservoir”). In theembodiment shown in FIGS. 3-A5, the pressure assembly 130 is a manualcontrol and includes a pressure valve 150 that is rotated to selectivelysiphon fluid via a bypass channel 139 from the pump body 136. Thepressure assembly 130 may also include a seal valve 152 that sealsagainst the pressure valve 150, as well as one or more sealing members,such as O-rings 154, 156 that ensure tight connections and help toprevent fluid from leaking around components.

The power assembly 144 is actuated by the actuation assembly 122 to turnthe oral irrigator on or off. In some embodiments, the power assembly144 may be an electrical switch, a mechanical switch, or a combination(electrical/mechanical) switch. With reference to FIGS. 3A-3C, in theseembodiments, the power assembly 144 includes a mechanical switch gear149 that engages a switch 142 electrically connected to power terminal147. Movement of the switch 142 closes or opens a connection between apower source (e.g., battery, wall power, etc.) and the motor 126. Thepower assembly 144 may also include a switch connector 145 that connectsthe switch gear 149 to the first actuation assembly 122 as discussed inmore detail below.

With reference to FIG. 5, both the power assembly 144 and the pressureassembly 130 are connected to the control housing 140. The controlhousing 140 connects to the pump body 136 and supports the powerassembly 144 and the pressure assembly 130 to connect with the actuationassemblies 122, 322 as discussed in more detail below.

First Actuation Assembly

The actuation assemblies 122, 322 actuate components in the base 102 ofthe irrigator 100. Turning to FIGS. 6A, 6B, 8A, 8B, 10A and 10C, thefirst actuation assembly 122 will be initially discussed first. Thefirst actuation assembly 122 may include a first grip enhancement member158, a first actuator 162, and a first bezel 166. Additionally, anaugmentation fluid 300 is received between the first bezel 166 and thefirst actuator 162.

FIGS. 10A-10C illustrates various views of the first bezel 166. Thefirst bezel 166 may include a main body 170 that may be generally ringshaped and define a receiving aperture 173 therethrough. A boss 256 mayextend outward from a center of the main body 170 to a distal end 254.One or more retention features 252 a, 252 b, 252 c may extend from anouter wall 177 of the boss 256. Additionally, a key element 250 mayextend along a length of the outer wall 177 of the boss 256.

The retention features 252 a, 252 b, 252 c are configured to engage withvarious aspects of the base 102 or housing of the oral irrigator. Asshown in FIG. 100, in one embodiment there are three retention features252 a, 252 b, 252 c spatially separated along the surface of the outerwall 177. In one embodiment, each of the retention features 252 a, 252b, 252 c may be differently shaped to engage with different componentsof the housing 103 and to prevent movement relative thereto. Forexample, a first retention feature 252 a and second retention feature252 b may be similarly shaped to one another and may taper in width froma first end 251 towards a second end 253, such the retention feature 252a, 252 b are wider closer to the key element 250. In this example, thethird retention feature 252 c may be formed as a rectangular tab.

Additionally, each of the retention features 252 a, 252 b, 252 c mayhave a larger base at the attachment to the outer wall 177 and decreasein area as they extend outward from the wall 177. For example, each ofthe retention features 252 a, 252 b, 252 c may have beveled edges 255 a,255 b, 255 c that are angled away from the distal end 254 of the boss256. In these instances, the beveled edges 255 a, 255 b, 255 c mayassist the insertion of the bezel 166 into the housing 103 and thevarying width helps to ensure that the bezel 166 remains secured inplace after it is inserted into the housing 103.

It should be noted that in other embodiments, the retention features 252a, 252 b, 252 c may be differently configured. For example, rather thanseparate features, an annular groove may extend around the boss 256.Fewer or more retention features may be used as well.

With continued reference to FIGS. 10A-10C, the bezel 166 also includes areception or interfacing surface 174. In one embodiment the interfacingsurface 174 may have a concave curved shape that curves radicallyoutward from a proximal end 175 of the main body 170. The curvilinearshape may be a complex concave surface (e.g., parabolic) curving outwardfrom a center of the main body 170. The shape of the interfacing surface174 may be varied as desired, but in some embodiments is selected tocorrespond to a shape of the actuator 162 in order to reduce noise andfriction between the two components. Further, the shape of theinterfacing surface 174 is selected to hold or retain a desired amountof augmenting fluid 300, and therefore may not exactly follow thecontour of the actuator 162 in order to define a space for theaugmenting fluid 300 there between.

The main body 170 may include a transition edge 176 between acylindrical outer surface 169 of the main body 170 and the interfacingsurface 174. The transition edge 176 may be formed as a substantiallyplanar surface that extends around a perimeter of the interfacingsurface 174. In some embodiments, a width of the outer surface 169 ofthe main body 170 varies as it extends around the main body 170. Forexample, as shown in FIG. 7A a first portion of the outer surface 169may be thicker than a second portion of the outer surface 169. The outersurface 169 may be otherwise varied to correspond to an aperture definedwithin the housing 103 and thus the example shown in FIGS. 7A, and10A-10C is illustrative only. The varying width of the outer surface 169helps to prevent the actuator from being coupled to the housing 103 inan upside down orientation.

It may also be appreciated that rather than being a separately moldedpart, the first bezel 166 may be formed as an integral part of thecontrol housing 140 or of the base 102. In addition, it may also beappreciated that the first actuator 162, described in further detailbelow, and the first bezel 166 may be made of different materials, suchthat one component may wear at a higher rate than the other. Forexample, the first bezel 166 may be made of an acetal thermoplasticwhereas the first actuator 162 may be formed of another plastic of adifferent hardness. Should the first actuator 162 and the first bezel166 be made from similar materials, the wear rate of each of thecomponents would be similar and undesired pitting on the surfaces ofeach component could occur.

The first actuator 162 of the first actuation assembly 122 will now bediscussed in more detail. FIGS. 12A-12D illustrates various views of thefirst actuator 162. The first actuator 162 may include a gripping body182 with an annular flange 178 extending therefrom and a control shaft180 extending from a distal end of the gripping body 182.

The gripping body 182 may be configured to be engaged by a user and maybe shaped as desired. In one embodiment, the gripping body 182 may becylindrically shaped and form a knob that can be rotated by a user. Thegripping body 182 may optionally be configured to receive and secure thegrip enhancement member 158 thereto. In these embodiments, the grippingbody 182 may include a plurality of nodules 280 that extend along alength of the outer surface of the gripping body 182. In someembodiments, the nodules 280 are formed as longitudinal ridges that arespatially separated around the outer surface of the gripping body 182. Aproximal end of the gripping body 182 defines a face 198. In oneembodiment, a surface of the face 198 may be convexly shaped.

With reference to FIGS. 6B, 8B and 12A, the gripping body 182 maytransition at the distal end to form the flange 178 and may include astep 187 positioned between the gripping body 182 and a proximal surface193 of the flange 178. The step 187 may be formed circumferentiallyaround the distal end of the gripping body 182 and may have a planar cutsurface 189 that transitions at an edge to define a curved surface 185between the top surface 189 and the planar proximal surface 193 of theflange 178. The proximal surface 193 may extend circumferentially aroundthe curved surface 185. The proximal surface 193 may extend to terminalsat an interface with a cylindrical side wall 179 of the flange 178.

With reference to FIGS. 6B and 8B, on the interior of the first actuator166, the gripping body 182 has a smooth transition to form the flange178. In particular, an interfacing surface 184 may be defined as acurved surface that extends from a distal end of the gripping body 182radically outward away from a center of the actuator 166. Theinterfacing surface 184 may have a curvature that substantially matchesa curvature of the first bezel 166 as discussed in more detail below,but generally may be convexly curved and extend away from the grippingbody 182. A lip 186 may be formed at the end of the interfacing surface184 and extend substantially parallel to the sidewall 179 of the flange178.

With reference to FIGS. 1 and 2, the flange 178 may be configured to bepositioned on an exterior of the housing 103 of the oral irrigator 100.In some embodiments, the proximal surface 193 includes an indicator 282,such as a raised protrusion, colored mark (e.g., dot, dash, or the likethat can be printed or otherwise defined on the actuator surface), orthe like. The indicator 282 may be provided to allow a user to assessthe position of the actuator 166 with respect to the internalcomponents, e.g., to illustrate the current state of the switch or thevalve connected to the actuator 166.

The control shaft 180 will now be discussed in more detail. Withreference to FIGS. 7A, 9A and 12A-12C, the control shaft 180 extendsfrom an interior surface 197 of the face 198 of the gripping body 182.In one embodiment, the control shaft 180 extends coaxially with theflange 178 and the gripping body 186. At least some portions of thecontrol shaft 180 may have a smaller cross-sectional dimension than theinner diameters of the flange 178 and the gripping body 182 such thatone or more cavity 188 may be defined between the outer surface 190 ofthe control shaft 180 and the interior surface of the gripping body 182.

As shown in FIGS. 12B and 12C, the control shaft 180 may have two planarsurfaces 190 a, 190 b. Two curved surfaces 191 a, 191 b may extendbetween edges of and connect the planar surfaces 190 a, 190 b. In someembodiments, the planar surfaces 190 a, 190 b may be angled such thatthe first curved surface 191 a may have a smaller arc length as comparedto the second curved surface 191 b. In one embodiment, the control shaft180 terminates at a distal end 196. The distal end 196 may define abeveled or angled “interior” edge 195. The interior edge 195 enhances aconnection between the control shaft 180 and the switch of the powerassembly 144 as discussed in more detail below. As shown in FIGS. 12A,12C, and 12D, one or more windows 194 a, 194 b may be defined in thecurved surfaces 191 a, 191 b. The windows 194 a, 194 b feature a foursided aperture that extends through the exterior surface 190 to aninterior surface 192 of the control shaft 180. The windows 194 a, 194 ballow various components of the actuation assembly 172 to snap-fit tothe control shaft 180.

With reference to FIGS. 6A, 6B, 8A and 8B, the first grip enhancementmember 158 increases a frictional connection between the user's handsand the actuation assembly 122. The grip enhancement member 158 mayinclude a textured pattern 202 or textured elements that extend aroundan outer surface of the grip enhancement member 158. In one embodiment,the textured pattern 202 is formed as diamond shaped ridges that aredefined, engraved, or otherwise formed into the surface of the gripenhancement 158.

The grip enhancement member 158 can be formed integrally with the firstactuator 166 or may be configured as a separate component therefrom. Inone embodiment, the grip enhancement member 158 is a cylindricallyshaped sleeve that is configured to slide over or wrap around andconnect to the first actuator 166. In these embodiments, the gripenhancement member 158 can be formed out of a different material fromthe first actuator 166, such as a more expensive material (e.g., metalversus plastic) and does not require a large cost increase for the unit.In these embodiments, an interior surface 204 of the grip enhancementmember 158 may be keyed to interface with the first actuator 166, or asshown in FIG. 8B, may be smooth and the grip enhancement member 158 mayhave a diameter configured to ensure a tight friction fit around thefirst actuator 166. In some instances the grip enhancement member 158can be plastic or a chrome plated plastic. However, it has been foundthat the tactile interaction between the grip enhancement member 158 andthe user may not provide adequate friction or tactile response withthese materials as compared to embodiments where the grip enhancementmember 158 is metal.

With reference to FIG. 6B, the augmentation fluid 300 is positionedwithin the gap 302 between interfacing surface 184 of the first actuator162 and the interfacing surface 174 of the first bezel 166. Theaugmentation fluid 300 modifies or varies the frictional relationshipbetween interfacing surfaces 174, 184 and may also absorb force,acoustical energy, or the like. In this manner, the augmentation fluid300 augments or varies the user experience in actuating the actuationassembly 122. Examples of augmentation fluid 300 include lithium grease,silicon grease, and other lubricants. Table 1 illustrates examples ofaugmentation fluids 300 that can be used including variouscharacteristics.

TABLE 1 Pene- Oil Evap- “Feel” Service tration Separation oration(Texture, Temp. (worked (24 hrs (24 hrs Product color) Range 60x) @ 100°C.) @ 100° C.) Fluoro- Ultra Light −45° C. 289 <0.17% 0.30% carbon(Smooth, to Gel Off White) 125° C. 868VL Fluoro- Very Light −40° C. 295<1.03% 0.20% carbon (Smooth, to Gel Off White) 125° C. 868L Fluoro-Light −40° C. 277 <0.0% 0.20% carbon (Smooth, to Gel Off White) 125° C.868 Fluoro- Medium −30° C. 265 <0.0% 0.20% carbon (Smooth, to Gel OffWhite) 125° C. 868H Fluoro- Heavy −20° C. 242 <0.0% 0.20% carbon(Smooth, to (un- Gel Off White) 125° C. worked) 868VH

Different characteristics of the augmentation fluid 300 can be changedto alter the user experience. For example, one characteristic of theaugmentation fluid 300 is viscosity and an augmentation fluid 300 with ahigher viscosity is more resistant to flow in response to friction orpressure than an augmentation fluid with a lower viscosity. In otherexamples, by changing the thickness, the density, the amount of fluidfilling the gap 302, etc., different friction and/or force profiles canbe generated. Similarly, varying the width, dimensions, and shape of thegap 302 will also change the user experience as this dimensionalvariation impacts the interaction of the augmentation fluid 300 betweenthe interfacing surfaces 174, 184, as the fluid will expand or compressinto the space. In one example, the gap is substantially any value below0.05″.

Second Actuation Assembly

With reference FIGS. 7A, 7B, 9A, 9B and 11 a-110, the second actuationassembly 322 will now be discussed in more detail. The second actuationassembly 322 is similar to the first actuation assembly 122, but mayinclude some structural differences. However, in some embodiments thetwo assemblies may be the same as one another. The second actuationassembly 322 may include a second grip enhancement member 358, a secondactuator 362, and a second bezel 366. Additionally, an augmentationfluid 500 is received between the second bezel 366 and the secondactuator 362.

FIGS. 11A-11C illustrates various views of the second bezel 366. Thesecond bezel 366 is generally similar to the first bezel 166, but mayinclude webbing and other structural differences. The second bezel 366includes a main body 370 that may be generally ring shaped and define areceiving aperture 373 therethrough. A boss 456 may extend outward froma center of the main body 370 to a distal end 454. One or more retentionfeatures 452 a, 452 b, and 452 c may extend from an outer wall 377 ofthe boss 456. Additionally, a key element 450 may extend along a lengthof the outer wall 377 of the boss 456.

The retention features 452 a, 452 b, and 452 c are configured to engagewith various aspects of the base 102 or housing of the oral irrigator100. In one embodiment, there are three retention features 452 a, 452 b,452 c spatially separated along the surface of the outer wall 377 of theboss 456. In one embodiment, each of the retention features 452 a, 452b, 452 c may be differently shaped to engage with different componentsof the housing 103 and to prevent movement relative thereto. Forexample, the first retention feature 452 a and the second retentionfeature 452 c may be similarly shaped to one another and may taper inwidth from a first end 451 a, 451 c toward a second end 453 a, 453 csuch that the retention features 452 a, 452 c are wider closer to thekey element 450. In this example, the third retention feature 452 b maybe formed as a rectangular tab.

Additionally, each of the retention features 452 a, 452 b, 452 c mayhave a larger base at the attachment to the outer wall 377 and decreasein area as they extend outward from the wall 377. For example, each ofthe retention features 452 a, 452 b, 452 c may have beveled edges 455 a,455 b, 455 c that are angled away from the distal end 454 of the boss456. In these instances, the beveled edges 455 a, 455 b, 455 c mayassist the bezel 366 to be inserted into the housing 103 and the varyingwidth helps to ensure that the bezel 366 remains secured in place afterit is inserted into the housing 103.

It should be noted that in other embodiments, the retention features 452a, 452 b, 452 c may be differently configured. For example, rather thanseparate features, an annular groove may extend around the boss 456.

With continued reference to FIGS. 11A-110, the bezel 366 also includes areception or interfacing surface 374 and a proximal end 375 of the mainbody 370. In one embodiment, the proximal end 375 may form a planarsurface. In one embodiment, the interfacing surface 374 may have aconcavely curved shape that curves radically outward from the proximalend 375. The curvilinear shape may be a complex concave surface (e.g.,parabolic) curving outward from a center of the main body 370. The shapeof the interfacing surface 374 may be varied as desired, but in someembodiments is selected to correspond to a shape of the actuator 362, asdiscussed in more detail below, in order to further reduce noise andfriction between the two components. Further, the interfacing surface374 may be curved to hold or retain the augmenting fluid 300 andtherefore may not exactly follow the contour of the actuator 362 inorder to define a space for the augmentation fluid 500 there between.

With continued reference to FIG. 11A, the main body 370 may include atransition edge 376 between a cylindrical outer surface 369 of the mainbody 370 and the interfacing surface 374. The transition edge 376 may beformed as a substantially planar surface that extends around a perimeterof the interfacing surface 374. In some embodiments, a width of theouter surface 369 of the main body 370 varies as it extends around themain body 370. For example, as shown in FIG. 9B, a first potion of theouter surface 369 may be thicker than a second portion of the outersurface 369. The outer surface 369 may be otherwise varied to correspondto an aperture defined within the housing 103 and the example shown inFIGS. 11A-11C is illustrative only.

The second bezel 366 may generally be similar to the first bezel 166 butwith a few structural differences. As shown in FIG. 11A, generally theproximal end 375 of the second bezel 366 is formed by a planar face 470that is parallel to a distal end 454. The second bezel 366 may also havewebbing 472 on the distal end 454, as shown in FIGS. 11B and 110. Thewebbing 472 decreases the amount of material used to form the secondbezel 366 such that the component may be lighter and more economical toproduce, while still providing sufficient structural strength.

It may also be appreciated that rather than being a separately moldedpart, the second bezel 366 may be formed as an integral part of thecontrol housing 140 or of the base 102. In addition, it may also befurther appreciated that the second actuator 362, as described infurther detail below, and the second bezel 366 may be made of differentmaterials, such that one component may wear at a higher rate than theother. Should the second actuator 362 and the second bezel 366 be madefrom similar materials, the wear rate of each of the components would besimilar and undesired pitting at the surfaces of each component mayform.

The second actuator 362 of the second actuation assembly 322 will now bediscussed in more detail. FIGS. 13A-13C illustrates views of the secondactuator 362. The second actuator 362 may include a gripping body 382with an annular flange 378 extending therefrom and a control shaft 380extending from a distal end of the gripping body 382.

The gripping body 382 of the second actuator 362 may be similar to thegripping body 182 of the first actuator 162. The gripping body 382 maybe configured to be engaged by a user and may be shaped as desired. Asshown in FIG. 13A, in this embodiment, the gripping body 382 may becylindrically shaped and form a knob that can be rotated by the user.The gripping body 382 may optionally be configured to receive and securethe grip enhancement member 358 thereto. In these embodiments, thegripping body 382 may include a plurality of nodules 480 that extendalong the length of the outer surface of gripping body 382. In someembodiments, the nodules 480 are formed as longitudinal ridges that arespatially separated around the outer surface of the gripping body 382. Aproximal end of the gripping body 382 may form a face 398 with aconvexly shaped surface.

With reference to FIGS. 7A-9A and 13A, the gripping body 382 maytransition at the distal end to form the flange 378 and may include astep 387 positioned between the proximal body 382 and a top surface 389of the flange 378. The step 387 may be formed circumferentially aroundthe distal end of the gripping body 382 and may have a planar topsurface 389 that transitions at an edge to define a curved surface 385between the top surface 380 and the planar proximal of the flange 378surface 393. The proximal surface 393 may extend circumferentiallyaround a perimeter of the curved surface 385. The proximal surface 393may extend to terminate as an interface with a cylindrical sidewall 379of the flange 378.

With reference to FIGS. 7B and 9B, on the interior of the secondactuator 362, the gripping body 382 may define a smooth transition toform the flange 378. In particular, an interfacing surface 384 may bedefined as a curved surface that extends from a distal end of thegripping body 382 radically outward away from a center of the actuator362. The interfacing surface 384 may have a curvature that substantiallymatches a curvature of the second bezel 366 as discussed in more detailbelow, but generally may be convexly curved and extend away from thegripping body 382. A lip 386 may be formed at the end of the interfacingsurface 384 and extend substantially parallel to the sidewall 379 of theflange 378.

As shown in FIGS. 1 and 2, the flange 378 may be configured to bepositioned on an exterior of the housing 103 of the oral irrigator 100.In some embodiments, the proximal surface 393 includes an indicator 482,such as a raised protrusion, colored mark (e.g., dot, dash, or the likeprinted or otherwise defined), or the like. The indicator 482 may beprovided to allow a user assess the position of the actuator 366 withrespect to the internal components, e.g., to illustrate the currentstate of the valve connected to the actuator.

The control shaft 380 will now be described in more detail. As shown inFIGS. 7B and 9B, the control shaft 380 extends from an interior surface397 of the face 398 of the gripping body 382. In one embodiment, thecontrol shaft 380 extends coaxially with the flange 378 and the grippingbody 386. At least some portions of the control shaft 380 may have asmaller cross-sectional dimension than the inner diameters of the flange378 and the gripping body 382 such that one or more cavities 388 may bedefined between the outer surface 390 of the control shaft 380 and theinterior surface of the gripping body 382.

As shown in FIGS. 13B and 13C, the control shaft 380 may have two planarsurfaces 390 a, 390 b. Two curved surfaces 391 a, 391 b may extendbetween edges of end connect the planar surfaces 390 a, 390 b. In someembodiments, the planar surfaces 190 a, 190 b may be angled, such thatthe first curved surface 391 a may have a smaller arc length as comparedto the second curved surface 391 b. In one embodiment, the control shaft380 terminates at a distal end 396. The distal end 396 may define abeveled or angled interior edge 395. The interior edge 395 enhances aconnection between the control shaft 380 and the pressure valve 150 ofthe pressure assembly 130 as discussed in more detail below. One or morewindows 394 a, 394 b may feature a four sided aperture that extendsthrough an outer surface 390 to an interior surface 392 of the controlshaft 380.

With reference to FIGS. 7A, 7B, 9A and 9B, the second grip enhancementmember 358 may increase a frictional connection between the user's handsand the actuation assembly 322. The grip enhancement member 358 mayinclude a textured pattern 402 or textured elements that extend aroundan outer surface of the grip enhancement member 358. In one embodiment,the textured pattern 402 is formed as diamond shaped ridges that aredefined, engraved, or otherwise formed into the surface of the gripenhancement 358.

The grip enhancement member 358 may be integrally formed with the secondactuator 362 or may be configured as a separate component therefrom. Inone embodiment, the grip enhancement member 358 may be a cylindricallyshaped sleeve that is configured to slide over or wrap around andconnect to the second actuator 362 as discussed in more detail below. Inthese embodiments, an interior surface 404 of the grip enhancementmember 358 may be keyed to interface with the second actuator 366 or asshown in FIG. 9B, may be smooth and the grip enhancement member 358 mayhave a diameter configured to ensure a tight friction fit around theactuator.

With reference to FIG. 7B, the augmentation fluid 500 is positionedwithin the gap 502 between interfacing surface 384 of the secondactuator 362 and the interfacing surface 374 of the second bezel 366.The augmentation fluid 500 is similar to the augmentation fluid 300 usedwithin actuator assembly 122. However, the augmentation fluid 500 may bevaried to include different characteristics than the augmentation fluid300 (e.g., it may have a different viscosity, or the like).

Operation of the Oral Irrigator

The overall assembly of the oral irrigator 100 will now be discussed.With reference to FIGS. 3A-5, the pump assembly 128, the pressureassembly 130, the power assembly 144, and the motor 126 are assembledand connected within the housing 103. For example, the pump valve 135 isreceived within the pump body 136, a drive linkage (not shown) isreceived within the gear assembly (not shown) and connected to a driveshaft (not shown) of the motor 126, and the chassis 132 is secured to abottom surface of the housing 103. The pump inlet 134 is positioned on atop inlet of the pump body 136 and connected thereto. The pressure valve150 of the pressure assembly 130 is connected to the pump body 136. Forexample, the pressure valve 150 is received within the cavity 137 of thepump body 136 as shown in FIG. 5.

The control housing 140 is then secured to the front of the pump body136. For example, fasteners are used to secure the two componentstogether. As shown in FIG. 5, the control housing 140 is connected tothe pump body 136 to allow a portion of the pressure valve 150 to extendtherethrough and be actuated by the actuation assemblies 122, 322.

The power assembly 144 is then connected to the control housing 140 andthe motor 126. For example, as shown in FIG. 3C, the power terminal 147and the switch 142 are connected to a first edge of the control housing140. The switch connector 145 is connected via a fastener 157 to theswitch gear 149 and extends through an aperture in the control housing140. In this manner, the switch gear 149, which is positioned on a backside of the control housing 140 can be actuated by a connection betweenthe first actuator 162 to the switch connector 145 positioned on thefront side of the control housing 140.

Once the internal components of the oral irrigator 100 are assembled,the housing 103 is positioned over the components and the sidewalls aresecured to the bottom surface. The reservoir 104 is then positioned on atop surface of the housing 103 and the pump inlet 134 extends throughand fluidly connects to the fluid container compartment 114. The hose110 is fluidly connected to the pump assembly 128 and the handle 102such that fluid pumped by the pump assembly 128 from the reservoir 104,flows into the hose 110 and out to the handle 102.

After the housing 103 is connected, the actuation assemblies 122, 322are connected to the housing 103. The bezel 166 is fitted into thehousing 103. The housing 103 features apertures that engage with theretention features 252 a, 252 b, 252 c of the bezel 166 shown in FIGS.10B and 10C. The shape of the retention features 252 a, 252 b, 252 cenhance the assembly process as the shape prevents movement of the bezel166 once assembled to the housing 103. Alignment of the bezel 166 withthe housing 103 is accomplished through a keyway or other alignmentfeature in the housing 103 that compliments the key element 250.

The augmentation fluid 300 is applied to the interfacing surface 184 ofthe actuator 162, the interfacing surface 174 of the bezel 166, or both.The control shaft 180 of the actuator 162 is then received through theaperture 173 of the bezel 166. The flange 178 is positioned adjacent tothe housing 103. The gap 302 is defined between the interfacing surfaces174, 184 filled with the augmentation fluid 300 as shown in FIG. 6B. Asindicated above, the width of the gap, as well as the amount of fluidpositioned within the gap can be varied based on a desired feel for theactuation assembly.

Once the actuator 162 is installed within the housing 103, the switchconnector 145 is connected to the control shaft 180, connecting thepower assembly 144 to the actuator 162. The beveled edge 195 of thecontrol shaft may enhance the assembly process as alignment of thevarious parts may be easier given the particular shape.

The first grip enhancement member 158 is received onto the gripping body182 until an end of the grip enhancement member 158 contacts the step187. The nodules 280 of the gripping body 182 engage with the insidesurface 204 of the grip enhancement member 158 to secure the gripengagement member 158 onto the gripping body 182. In one embodiment, thenodules 280 have an effective outer diameter that is slightly greaterthan the diameter of the inside surface 204 and create an interferencefit with the grip enhancement member 158 when it is connected to thegripping body 182 due to the compression of the nodules 280 by theinside surface 204. Adhesive can additionally be used to secure the gripengagement member 158 to the gripping body 182.

The actuation assemblies can be installed simultaneously or in any orderdesired. In one embodiment, once the first actuation assembly 122 isconnected to the housing 103, the second actuation assembly 322 may beconnected to the housing 103. The housing 103 such that the housing 103defines apertures that engage with the retention features 452 a, 452 b,452 c of the bezel 366 shown in FIGS. 11B and 110 the bezel 366 to thehousing 103. That is, the retention features 452 a, 452 b, 452 c arefrictionally fit into and engage corresponding features on the housing103. The retention features 452 a, 452 b, 452 c help to prevent movementof the bezel 166 once assembled to the housing 103 by keying to thehousing 103. The bezel 366 is aligned with the housing 103 through akeyway or other alignment feature in the housing 103 that complimentsthe key element 450.

The augmentation fluid 500 is applied to the interfacing surface 384 ofthe actuator 362, the interfacing surface 374 of the bezel 366, or both.The control shaft 380 of the actuator 362 is then received through theaperture 373 of the bezel 366. The flange 378 is thereby positionedadjacent to the housing 103. The gap 502 filled with the augmentationfluid 500 is then formed between the interfacing surfaces 374, 384, asshown in FIG. 7B.

Once the actuator 362 is installed within the housing 103, the pumpvalve 150 is connected to the control shaft 380, connecting the pressureassembly 130 to the actuator 362. The beveled edge 395 of the controlshaft 380 may enhance the assembly process. The second grip enhancementmember 358 is received onto the gripping body 382 until an end of thegrip enhancement member 358 contacts the step 387. The connection of thegripping body 382 and the grip enhancement member 358 may be similar tothe connection of the gripping body 182 and the grip enhancement member158, such that the nodules 480 of the gripping body 382 engage with theinside surface 404 of the grip enhancement member 358 to secure the gripengagement member 358 onto the gripping body 382 by an interference fit.As before, adhesive may also be used.

To operate various features of the oral irrigator 100, a user engagesthe actuation assembly 122 to turn the oral irrigator on and off. Tooperate the assembly 122, a user grasps the first grip enhancementmember 158 and rotates the first grip enhancement member, which in turnrotates the first actuator 162. This causes the mechanical switch gear149 to rotate, correspondingly interfacing with the switch 142 on thepower terminal 147.

As the user continues to rotate the first actuator 162 in the firstdirection, the mechanical switch gear 149 moves the switch 142 tocomplete a power circuit within the power terminal 147. This enablespower to be supplied to the motor 126, causing the motor to rotate,moving the gear assembly. The gear assembly causes the pump assembly 128to pull fluid from the fluid container compartment 114 of the reservoir104 and push it to the tip 108.

To turn the oral irrigator 100 off, the user grasps the first gripenhancement member 158 and rotates in a second direction. This causesthe first actuator 162 to rotate, moving the mechanical switch gear 149.Movement of the mechanical switch gear 149 in the second direction movesthe switch 142 to a second position, disconnecting the power circuitwithin the power terminal 147.

The user engages the actuation assembly 322 to vary the pressure of thefluid expelled from the tip 108. To operate the actuation assembly 322,the user grasps the second grip enhancement member 358 and rotates it inthe first direction. This rotation rotates the second actuator 362connected thereto. The rotation of the second actuator 362 causes thebypass valve 150 to rotate, causing fluid within the pump body 136 to besiphoned through a bypass channel 139, reducing the pressure of thefluid supplied to the tip 108. When the bypass valve 150 is in a closedposition, no fluid is siphoned through the bypass channel 139, and thefluid supplied to the tip 108 is at the highest pressure. When thebypass valve 150 is adjusted towards a semi-open or open position, fluidis siphoned away from the pump assembly such that the pressure of thefluid being supplied to the tip 108 is decreased. Because the actuationassembly 322 is rotatable, the user can achieve multiple differentpressure levels by positioning the actuator at various locations.

When adjusting the actuation assembly 122, 322, the interaction ofinterfacing surfaces 174, 374 and 184, 384 with the augmentation fluid300, 500 allows the user to experience a smooth sensation whenrotationally adjusting the actuation assembly. As mentioned above,changing various characteristics of the augmentation fluid 300, 500 andthe gap 302, 502 creates different user experiences. For example, insome embodiments, an augmentation fluid 300 with a higher viscosity maybe used while the volume of fluid 300 remains constant. As such, if noother components are altered, the user may expend more effort tosmoothly adjust the actuator assembly 122, as the higher viscosity ofthe augmentation fluid 300 increases the friction generated during themovement of interfacing surface 184 about the interfacing surface 174,thereby impeding the rotation of the interior interfacing surface 184about the interfacing surface 174. The use of an augmentation fluid 500with a higher viscosity would yield a similar result to a user operatingactuation assembly 322.

In some embodiments, an augmentation fluid 300 with a lower viscositymay be used while the volume of fluid 300 remains constant. As such, ifno other components are altered, the user may expend less effort tosmoothly adjust the actuator assembly 122, as the lower viscosity of theaugmentation fluid 300 decreases the friction generated during themovement of interfacing surface 184 about interfacing surface 174,thereby facilitating the rotation of the interfacing surface 184 aboutthe interfacing surface 174. The use of an augmentation fluid 500 with alower viscosity would yield a similar result to a user operatingactuation assembly 322.

In some embodiments, the width of the gap 302 may be widened but thesame volume of augmentation fluid 300 may be used. In this embodiment,the effective viscosity of the augmentation fluid 300 may be decreasedas the augmentation fluid 300 may not coat the entire interfacingsurface 184 and the interfacing surface 174 and also fill the gap 302. Auser may expend less effort to smoothly adjust the first actuatorassembly 122, facilitating the rotation of the interfacing surface 184about the interfacing surface 174. The use of an augmentation fluid 500with a larger gap 502 would yield a similar result to a user operatingactuation assembly 322.

In some embodiments, the width of the gap 302 may be narrowed, while thesame volume of augmentation fluid 300 may be used. In this embodiment,the effective viscosity of the augmentation fluid may be increased dueto the increased pressure transmitted on the augmentation fluid becausethe width of the gap 302 is smaller. The increase in the effectiveviscosity will inhibit the rotation of the interfacing surface 184 aboutthe interfacing surface 174, making the actuator assembly 122 moredifficult to actuate. The use of an augmentation fluid 500 with asmaller gap 502 would yield a similar result to a user operatingactuation assembly 322.

In all cases, the type and viscosity of augmentation fluid 300, 500chosen should have adequate surface tension with respect to the width ofthe gaps 302, 502 such that the augmentation fluids 300, 500 do not leakor flow out of the gaps, but rather are retained in the gaps 302, 502under normal environmental operating temperature ranges and atmosphericpressure ranges.

The oral irrigator 100 may be used in a wet environment. Therefore, theexternal portions of the first actuation assembly 122 and the secondactuation assembly 322 may become damp or wet. The first gripenhancement member 158 and second grip enhancement member 358 provide asuperior consumer experience regardless if the environment is dry, damp,or wet; or allowing a user to grip the assemblies firmly due to thepatterned grip surfaces.

CONCLUSION

The foregoing description has broad application. For example, whileexamples disclosed herein may focus on two actuation assemblies, itshould be appreciated that the concepts disclosed herein may equallyapply to other irrigating devices, such as handheld units or portableunits. Accordingly, the discussion of any example is meant only to beexemplary and is not intended to suggest that the scope of thedisclosure or the claims is limited to these examples.

All directional references (e.g., proximal, distal, upper, lower,upward, downward, left, right, lateral, longitudinal, front, back, top,bottom, above, below, vertical, horizontal, radial, axial, clockwise,and counterclockwise) are only used for identification purposes to aidthe reader's understanding of the present invention, and do not createlimitations, particularly as to the position, orientation, or use of theinvention. Connection references (e.g., attached, coupled, connected,and joined) are to be construed broadly and may include intermediatemembers between a collection of elements and relative movement betweenelements unless otherwise indicated. As such, connection references donot necessarily infer that two elements are directly connected and infixed relation to each other. The exemplary drawings are for purposes ofillustration only and the dimensions, positions, order, and relativesizes reflected in the drawings attached hereto may vary.

The above specification, examples, and data provide a full descriptionof the structure and use of exemplary embodiments of the invention asdefined in the claims. Although various embodiments of the claimedinvention have been described above with a certain degree ofparticularity, or with reference to one or more individual embodiments,those skilled in the art could make numerous alterations to thedisclosed embodiments without departing from the scope of the claimedinvention. Other embodiments are therefore contemplated. It is intendedthat all matter contained in the above description and shown in theaccompanying drawings shall be interpreted as illustrative only ofparticular embodiments and not limiting. Changes in detail or structuremay be made without departing from the basic elements of the inventionas defined in the following claims.

What is claimed is:
 1. An actuation assembly for an oral irrigatorcomprising: a bezel positioned at least partially within and secured toa housing of the oral irrigator and comprising a bezel interfacingsurface; and an actuator operably connected to the bezel and moveablerelative thereto and comprising an actuator interfacing surface, theactuator comprising: a cylindrical body; a face extending across an endof the cylindrical body to define a front wall, the face having aninterior surface oriented towards the housing and an exterior surfaceoriented away from the housing; and a control shaft integrally formedwith and directly extending from the interior surface of the face alonga central axis of the face, wherein movement of the cylindrical bodycauses the control shaft to directly actuate a switch within thehousing; and an augmentation fluid positioned between the bezel and theactuator; wherein the augmentation fluid modifies a frictionalrelationship between the bezel and the actuator to provide a predefinedresistance force between the actuator and the bezel as the actuator isrotated relative to the bezel.
 2. The actuation assembly of claim 1,wherein: the bezel is annular in shape and the bezel interfacing surfaceis formed as a concave annular trough; and the actuator interfacingsurface is annular in shape and is formed as a convex annular trough,such that a curvature of the concave annular trough corresponds to acurvature of the convex annular trough.
 3. The actuation assembly ofclaim 2, wherein the actuator is at least partially separated from thebezel by the augmentation fluid.
 4. The actuation assembly of claim 2,wherein a portion of the actuator contacts a portion of the bezelwithout augmentation fluid therebetween.
 5. The actuation assembly ofclaim 2, wherein the bezel further defines an annular, planar surfaceadjacent to the bezel interfacing surface and positioned inside an innerradius of the concave annular trough.
 6. The actuation assembly of claim1, wherein: the actuator is made of a first plastic material with afirst hardness; and the bezel is made of a second plastic material witha second hardness different from the first hardness.
 7. The actuationassembly of claim 1, wherein the bezel is formed integrally with thehousing for the oral irrigator.
 8. The actuation assembly of claim 1,wherein: the bezel defines an annular boss extending distally in anopposite direction from the bezel interfacing surface; and a number ofretention features extend radially outward from a distal end of theannular boss configured for engagement with opposing apertures in thehousing of the oral irrigator.
 9. The actuation assembly of claim 8,wherein a key feature extends radially outward from a distal end of theannular boss configured for insertion through an opposing keyway in thehousing of the oral irrigator.
 10. The actuation assembly of claim 1,further comprising a grip enhancement member defining a sleevepositioned around an outer surface of the cylindrical body.
 11. Theactuation assembly of claim 1, wherein: the bezel defines a centralaperture; and the control shaft extends through the central aperture ofthe bezel and is mechanically coupled to the switch and configured tomove the switch.
 12. The actuation assembly of claim 1, wherein theexterior surface of the face defines a smooth terminal surface of theactuator.
 13. The actuation assembly of claim 1, wherein the cylindricalbody extends coextensively with the control shaft and the control shaftextends through the bezel and the housing of the oral irrigator.
 14. Anoral irrigator comprising: a fluid reservoir; a housing configured tosupport the fluid reservoir; a pump positioned within the housing havingan inlet fluidly connected to the fluid reservoir and an outlet; a motorpositioned within the housing that drives the pump; a power sourcepositioned within the housing that provides electricity to the motor; anirrigator handle with a fluid outlet fluidly connected via a hose to theoutlet of the pump; a first bezel positioned at least partially withinand secured to the housing, received within a first opening in thehousing, and defining a central aperture within the first bezel, thefirst bezel comprising a first bezel interfacing surface; a firstactuator operably connected to the first bezel and moveable relativethereto, wherein the first actuator further comprises: a cylindricalbody; a face extending across an end of the cylindrical body to define afront wall, the face having an interior surface oriented towards thehousing and an exterior surface oriented away from the housing; and afirst control shaft integrally formed with and directly extending fromthe interior surface of the face along a central axis of the face,wherein movement of the cylindrical body causes the first control shaftto directly actuate a switch within the housing; and a first actuatorinterfacing surface; and a first augmentation fluid is positionedbetween the first bezel and the first actuator; wherein the firstaugmentation fluid modifies a frictional relationship between the firstbezel and the first actuator to provide a predefined resistance forcebetween the first actuator and the first bezel as the first actuator isrotated relative to the first bezel.
 15. The oral irrigator of claim 14,wherein: the first bezel is annular in shape and the first bezelinterfacing surface is formed as a concave annular trough; and the firstactuator interfacing surface is annular in shape and is formed as aconvex annular trough, such that the concave annular trough correspondsto the convex annular trough.
 16. The oral irrigator of claim 14,further comprising: a second bezel secured to or formed as part of thehousing, positioned about a second opening in the housing, and defininga central aperture within the second bezel; a second actuator operablyconnected to the second bezel and moveable relative thereto, wherein thesecond actuator further comprises a second control shaft that extendsthrough the central aperture in the second bezel and the second openingin the housing and is operably connected to a valve that controls fluidpressure of a fluid traveling from the pump to the handle; and a secondaugmentation fluid is positioned between the second bezel and the secondactuator; wherein the second augmentation fluid modifies a frictionalrelationship between the second bezel and the second actuator to providea predefined resistance force between the second actuator and the secondbezel as the second actuator is rotated relative to the second bezel.17. The oral irrigator of claim 16, wherein: the second bezel comprisesa second bezel interfacing surface; the second actuator comprises asecond actuator interfacing surface; and a curvature of the second bezelinterfacing surface corresponds to a curvature of the second actuatorinterfacing surface.
 18. The oral irrigator of claim 17, wherein: thesecond bezel is annular in shape and the second bezel interfacingsurface is formed as a concave annular trough; and the second actuatorinterfacing surface is annular in shape and is formed as a convexannular trough.
 19. The oral irrigator of claim 16, wherein the firstaugmentation fluid has a first viscosity that is different from a secondviscosity of the second augmentation fluid.
 20. The oral irrigator ofclaim 14, wherein the housing defines a cavity and the pump ispositioned within the cavity; and the first bezel is positioned withinthe first opening of the housing such that an edge of the housingengages an outer surface of the first bezel and a portion of the bezelis positioned against an exterior surface of the housing and a portionof the bezel is positioned against an interior surface of the housing.21. The oral irrigator of claim 14, wherein the first control shaft issecured to the switch and configured to actuate the switch with thehousing.